All terrain vehicle with improved air intake

ABSTRACT

An all terrain vehicle contains a partition wall which partitions a passenger space and a hood which is arranged ahead of the partition wall. When viewed from the side of the vehicle, an air outlet of an exhaust passage is opened in an upper space located between the partition wall and the hood.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an all terrain vehicle including anengine and a belt-type continuously variable transmission which variesrotating speeds of the engine to output power, having an improved airintake.

2. Description of Related Art

Generally, an all terrain vehicle with a mounted engine unit having anintegrated engine and a belt-type continuously variable transmissionincludes a cooling unit which supplies cooling air into the continuouslyvariable transmission to cool a belt. As disclosed in U.S. Pat. No.5,086,858, an engine unit is mounted behind a seat, a cooling air intakeport is formed in a front end portion of a transmission case containingthe belt-type continuously variable transmission in the engine unit, anda cooling air outlet port is formed in a rear end portion. Air issupplied to the cooling air intake from an upper portion of a pillarframe arranged upright behind the seat, and cooling air is dischargedfrom the cooling air outlet to the rear side of the vehicle.

In the prior art, the cooling air is directly discharged from thecooling air outlet of the transmission case to the rear side of thevehicle. For this reason, exhaust sounds from the outlet canunfortunately be easily transmitted to a passenger sitting on the seatas a harsh noise.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the prior art,and has as its object to provide an all terrain vehicle which caninhibit exhaust sound from being transmitted to a passenger when coolingair is discharged.

According to an aspect of the present invention, there is provided anall terrain vehicle including: a body frame; a pair of left and rightwheels and at least one pair of left and right rear wheels which aresupported by the body frame; a partition wall arranged behind the frontwheel in a front/rear direction of the vehicle; a seat which is arrangedbehind the partition wall in the front/rear direction of the vehicle andon which a passenger sits; an engine which is arranged behind thepartition wall in the front/rear direction of the vehicle and abelt-type continuously variable transmission which varies rotatingspeeds of the engine to output power, the engine and the belt-typecontinuously variable transmission being mounted on the body frame; ahood having at least a part located ahead of the partition wall in thefront/rear direction of the vehicle, and located above the front wheel;a cooling air passage which supplies cooling air into the continuouslyvariable transmission; and an exhaust passage which has an air outletlocated ahead of at least a part of the partition wall and below thehood and discharges the cooling air from an inside of the continuouslyvariable transmission.

According to the vehicle of the present invention, since an air outletof an exhaust passage which discharges air which cools the belt-typecontinuously variable transmission is opened ahead of at least a part ofthe partition wall and below the hood, exhaust sound from the air outletis insulated by the partition wall and the hood. Therefore, noise can beinhibited from being transmitted to a passenger.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an all-terrain vehicle according to anembodiment of the present invention;

FIG. 2 is a side view of a body frame on which an engine unit of thevehicle is mounted;

FIG. 3 is a plan view of the body frame;

FIG. 4 is a side view of the engine unit;

FIG. 5 is a plan view of the engine;

FIG. 6 is a plan view of a housing box mounted on the body frame;

FIG. 7 is a side view of the housing box;

FIG. 8 is a perspective view of the housing box; and

FIG. 9 is a plan view showing an arrangement state of a floor, a tunnelportion, an engine unit, and respective passages.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be described below withreference to the accompanying drawings.

FIGS. 1 to 9 are views to explain an all-terrain vehicle according to anembodiment of the present invention. In the embodiment, front, rear,ahead, behind, left, right, above, and below, unless otherwise noted,are from the perspective of a passenger sitting on a seat. Also, asshown in the Figures like parts are identified with the same numeral.The front wheels are the same on both the left and right sides, so theyare referenced by like numeral 3. In some instances only the left sideof the vehicle is shown, but it is understood that similar items on theright side, while not shown, are of similar nature.

In the drawings, reference numeral 1 denotes an all-terrain vehicle. Thevehicle 1 includes a body frame 2, an engine unit 3 mounted on the bodyframe 2, front wheels 4 arranged at left and right front ends of thebody frame 2, and rear wheels 5 arranged at left and right rear ends.

The body frame 2 includes a main frame 2 a which extends in thefront/rear direction of the vehicle to have a ladder-like shape and onwhich the left and right front wheels 4, the left and right rear wheels5 and the engine unit 3 are arranged, left and right pillar frames 2 bwhich are arranged upright on left and right outer ends of a front/rearcenter portion of the main frame 2 a and which form a vehicle chamber(passenger space) A together with the main frame 2 a, a front frame 2 cwhich is arranged upright ahead of the vehicle chamber A to configure afront chamber B, and a loading space frame 2 e arranged upright behindthe vehicle chamber A.

The main frame 2 a has left and right center members 12 extending in thefront/rear direction of the vehicle and front and rear cross members 14which connect front ends and rear ends of the left and right centermembers 12 to each other. Middle portions of the left and right centermembers 12 are connected to each other by planar center cross members13. The engine unit 3 is mounted on the planar center cross members 13.

Outer ends of the front and rear cross members 14 in the front/reardirection of the vehicle are connected to the pillar frames 2 b.

The pillar frames 2 b have left and right pillar members 15 where frontand rear entrances 15 a and 15 b are formed, and a plurality of roofmembers 16 which connect upper sides of the left and right pillarmembers 15 to each other.

The front frame 2 c, as shown in FIG. 6 and FIG. 8, has first and secondcross frames 45 and 46, first and second center frames 47, and first andsecond side frames 48. The first cross frame 45 is arranged near thefront end of the vehicle chamber A and above the main frame 2 a, andextends in the width direction of the vehicle to connect the left andright pillar members 15, 15 to each other. The second cross frame 46 isarranged ahead of the first cross frame 45 to extend in the widthdirection of the vehicle. The first and second side frames 48 arearranged to extend in the front/rear direction of the vehicle at a leftside portion and a right side portion in the width direction of thevehicle. The first and second center frames 47 extend in the front/reardirection of the vehicle inside the side frame in the width direction ofthe vehicle and connect the first cross frame 45 to the second crossframe 46. The front ends of the first and second center frames 47 areconnected to the front end of the main frame 2 a by left and right stays47 a.

The loading space frame 2 e has stays 2 f arranged upright near the rearend of the main frame 2 a, side frames 2 g supported by the stays 2 f,and a plurality of cross frames 2 h which connect the side frames 2 g toeach other.

A first seat 6 is mounted substantially on a center portion of the mainframe 2 a in the front/rear direction of the vehicle, and a second seat7 is mounted on a front portion of the loading space frame 2 e. Aloading space 10 is arranged behind the second seat 7 of the loadingspace frame 2 e. A first floor 8 is arranged on a forward portion of thefirst seat 6 of the main frame 2 a.

The first seat 6 is configured by left and right seats 6 a and 6 barranged with a predetermined gap in the width direction of the vehicle.The engine unit 3 is mounted between the left and right seats 6 a and 6b.

Each of the left and right seats 6 a and 6 b has a seat cushion 6 c anda seat back 6 d, and a steering wheel 17 is arranged ahead of the leftseat 6 a.

The second seat 7 is arranged at a position substantially as high as thefirst seat 6, and has a bench seat cushion 7 a and a seat back 7 b fortwo passengers. A headrest 7 c is arranged above the seat back 7 b.

The vehicle 1 includes a partition wall 23 which is arranged behind thefront wheels 4 in the front/rear direction of the vehicle to partitionthe vehicle 1 to form the vehicle chamber A and the front chamber B. Thefront chamber B is a space in front of the partition wall 23 and below ahood 25. The hood 25 is at least partially located ahead of thepartition wall 23 in the front/rear direction of the vehicle, and islocated above the front wheels 4. Left and right first floors(footrests) 8 for the passengers to place their feet are arrangedbetween the partition wall 23 and the left and right seats 6 a and 6 b.Between the left and right first floors 8 in the width direction of thevehicle, a console 24 having an interior projects upward extending inthe form of a tunnel substantially from the center portion of thepartition wall 23 in the width direction of the vehicle to the rear sideof the vehicle in the front/rear direction of the vehicle, andcommunicating with the front chamber B is arranged. An upper end 24 a ofthe console 24 is arranged at a position slightly higher than a seatlevel of the first seat 6.

The partition wall 23 is arranged at a front end of the pillar frames 2b, and has an upper portion 23 a on which gauges (not shown) such as aspeedometer are arranged, an intermediate portion 23 b extendingdiagonally forward from the upper portion 23 a to the lower side, and alower portion 23 c extending diagonally backward from the intermediateportion 23 b to the lower side. An accelerator pedal and a brake pedal(not shown) are arranged in the lower portion 23 c. Front ends of thefirst floors 8 are connected to the rear end of the lower portion 23 c.

The engine unit 3 is arranged in the interior space of console 24. Theengine unit 3 includes a water-cooled four-cycle engine 20, a V-beltcontinuously variable transmission 21 which continuously varies arotating speed of the engine 20, and a cooling unit 28 which cools thecontinuously variable transmission 21.

The engine 20 is obtained by stacking a cylinder body 20 g and acylinder head 20 c on a crank case 20 f and connecting the cylinder body20 g and the cylinder head 20 c to each other. The continuously variabletransmission 21 is connected to a side portion of the crank case 20 f.

The engine 20 is arranged on a center portion of the left and right sidemembers 12 in the front/rear direction of the vehicle and between theleft and right seats 6 a and 6 b of the first seat 6. A crank shaft 20 aof the engine 20 almost horizontally faces in the width direction of thevehicle, and a cylinder shaft line 20 b faces diagonally backward andupward.

The engine 20 partially overlaps the first seat 6 when viewed from aside of the vehicle. More specifically, the cylinder head 20 c of theengine 20 is arranged to overlap the seat cushion 6 c.

The engine 20 is mounted such that an intake port 20 d opened on a frontside wall of the cylinder head 20 c faces the front side of the vehicleand an exhaust port 20 e open on a rear side wall faces the rear side ofthe vehicle (see FIG. 4).

An intake pipe (intake passage) 30 is connected to the intake port 20 dof the cylinder head 20 c. The intake pipe 30 extends from the intakeport 20 d to the front side of the vehicle to supply combustion air intothe engine 20. An exhaust pipe (exhaust passage) 31 is connected to theexhaust port 20 e. The exhaust pipe 31 extends from the exhaust port 20e to the rear side of the vehicle to discharge exhaust gas to the rearside of the vehicle. The intake pipe 30 and the exhaust pipe 31 arealmost linearly arranged substantially along a center line of thevehicle in the front/rear direction when viewed from the above.

The exhaust pipe 31 includes a first vertical pipe portion 3 lb almostvertically extending from a connection unit 31 a connected to thecylinder head 20 c to the lower side, a horizontal pipe portion 31 cextending from a lower end of the first vertical pipe portion 31 b tothe rear side under a second floor 9, a second vertical pipe portion 31d extending upright from a rear end of the horizontal pipe portion 31 cto the upper side, and an extending portion 31 e extending from an upperend of the second vertical pipe portion 31 d to the rear side of thevehicle between the second seat 7 and a rear wheel drive shaft 5 a ofthe rear wheels 5.

The exhaust pipe 31 includes a muffler 36 connected to a rear end of theextending portion 31 e and arranged in the rear of the second seat 7.The muffler 36 has an elliptic shape having a vertical dimension largerthan a horizontal dimension, and arranged to have an axial line alongthe width direction of the vehicle.

The intake pipe 30 is connected to the cylinder head 20 c through athrottle body 32 having a fuel injection valve 33.

In the middle of the intake pipe 30, a surge tank 34 is interposed. Thesurge tank 34 is arranged ahead of the engine 20 in the tunnel portion24. An air cleaner 35 is connected to the surge tank 34 through anintake air supply pipe 30 a. The surge tank 34 has a capacity largerthan that of the air cleaner 35.

The air cleaner 35 is arranged at a center portion in the widthdirection of the vehicle and at a portion surrounded by the upperportion 23 a and the intermediate portion 23 b of the partition wall 23and the hood 25 in the front chamber B in a side view.

The intake port 35 a is connected and formed on a rear wall of the aircleaner 35. The intake port 35 a is located at a position higher than anupper end 4 b of the front wheel 4 and formed in a portion surrounded bythe intermediate portion 23 b of partition wall 23 and the hood 25,preferably facing rearward.

The continuously variable transmission 21 has a transmission case 21 aconnected to a left side of the engine 20 in the width direction of thevehicle and extending from the engine 20 to the front side, a drivepulley 21 b housed in the transmission case 21 a and attached to thecrank shaft 20 a of the engine 20, a driven pulley 21 d attached to anoutput shaft 21 c which is parallel to the crank shaft 20 a, and aV-belt 21 e wound on the drive pulley 21 b and the driven pulley 21 d.

A front power transmission shaft 22 a extending forward and a rear powertransmission shaft 22 b extending backward are connected to the outputshaft 21 c. The front and rear power transmission shafts 22 a, 22 b areconnected to the front and rear wheel drive shafts 4 a and 5 a throughfront and rear differential devices 22 c, 22 d, respectively.

The cooling unit 28 includes a cooling air supply duct (cooling airpassage) 40 which supplies cooling air into the continuously variabletransmission 21, and a cooling air exhaust duct (exhaust passage) 41which discharges cooling air, and has a structure as described below indetail.

An air inlet port 21 f is formed in a portion, facing the output shaft21 c, of a left outer side wall of the transmission case 21 a. An airexhaust port 21 g, facing the drive pulley 21 b, is formed in a portionof an upper wall portion. The cooling air supply duct 40 is connected tothe air inlet port 21 f, and the cooling air exhaust duct 41 isconnected to the air exhaust port 21 g.

On a circumferential surface of the drive pulley 21 b, a large number offins (not shown) are formed in a circumferential direction. The drivepulley 21 b rotates to take cooling air in the transmission case 21 a.

The cooling air supply duct 40 has a first inlet portion 40 b extendingfrom the air inlet port 21 f and curving to the inside in the widthdirection of the vehicle, a second inlet portion 40 c extending from thefirst inlet portion 40 b and passing through a portion below the surgetank 34, a third inlet portion 40 d extending from the second inletportion 40 c to rise up on a front side of the surge tank 34, and afourth inlet portion 40 e extending from the third inlet portion 40 dand curving to the right side in the width direction of the vehicle. Anair inlet port 40 a is formed in the fourth inlet portion 40 e.

The air inlet port 40 a is located at a position higher than the upperend 4 b of the front wheel 4 and formed near a right side wall of theair cleaner 35 above the front chamber B in the width direction of thevehicle underneath hood 25.

The air inlet port 40 a, as shown in FIGS. 6 to 8, is connected to anair intake port 43 d defined in a housing box 43 which houses in-vehicleparts attached to the front frame 2 c, and has the following structureas described below in detail.

The housing box 43 is arranged at a portion surrounded by the firstcross frame 45, the second cross frame 46, the second side frames 48,and the second center frame 47 of the front frame 2 c. The housing box43 has a housing box body 43 a in which in-vehicle parts such as abattery 49 and various electronic parts 50 are housed, and a housing boxcover 43 b attached to the housing box body 43 a to cover the upper sidethereof.

An air inhalant port 43 c is formed on a front end of the housing boxcover 43 b to open forward, and an air intake port 43 d is formed in arear end of an inner wall thereof. The air inlet 40 a of the cooling airsupply duct 40 is connected to the air intake port 43 d. In this manner,air which has cooled the battery 49 and the electronic parts 50 issupplied into the transmission case 21 a through the cooling air supplyduct 40.

The cooling air exhaust duct 41 has a first exhaust portion 41 bextending from the air exhaust port 21 g to be diagonally forward andcurved towards the lower side below the intake pipe 30, a second exhaustportion 41 c extending from the first exhaust portion 41 b below thesurge tank 34 almost in parallel to the second inlet portion 40 c, athird exhaust portion 41 d extending from the second exhaust portion 41c to rise up on a front side of the surge tank 34 almost in parallel tothe third inlet portion 40 d, a fourth exhaust portion 41 e extendingfrom the third exhaust portion 41 d to be curved to the left side in thewidth direction of the vehicle, and a fifth exhaust portion 41 fextending from the fourth exhaust portion 41 e and then diagonallybackward extending to the lower side. An air outlet 41 a is defined atthe end of the fifth exhaust portion 41 f directed downward andrearwardly.

The air outlet 41 a is located at a position higher than the upper end 4b of the front wheel to open in the upper portion of the front chamber Bdownward and backward.

The intake pipe 30 and the surge tank 34 are arranged to be positionedabove the cooling air supply duct 40 and the cooling air exhaust duct41.

When viewed from the upper side of the vehicle, the intake pipe 30partially overlaps the cooling air supply duct 40 and the cooling airexhaust duct 41, and the surge tank 34 partially overlaps the coolingair supply duct 40 and the cooling air exhaust duct 41. The intake pipe30, the surge tank 34, the cooling air supply duct 40, and the coolingair exhaust duct 41 overlap the console 24 at the same time. Morespecifically, the intake pipe 30 overlaps the first exhaust portion 41b, and the surge tank 34 overlaps the second inlet portion 40 c and thesecond exhaust portion 41 c.

The intake port 35 a of the air cleaner 35 vertically overlaps the thirdinlet portion 40 d and the third exhaust portion 41 d. The intake airsupply pipe 30 a is located between the third inlet portion 40 d and thethird exhaust portion 41 d.

The air inlet port 40 a and the air outlet 41 a open in a portion abovethe front chamber B, the portion being surrounded by the upper portion23 a and the intermediate portion 23 b of the partition wall 23 and thehood 25. The air inlet port 40 a and the air outlet 41 a are separatelyarranged on one side and the other side with reference to the centerline of the vehicle in the width direction of the vehicle. Morespecifically, the air inlet port 40 a and the air outlet 41 a are spacedapart from each other with an interval which is ½ or more of thedimension in width of the vehicle.

According to the present embodiment, the air outlet 41 a of the coolingair exhaust duct 41 which discharges air that has cooled thecontinuously variable transmission 21 is located ahead of the partitionwall 23 and below the hood 25. For this reason, exhaust sound from theair outlet 41 a is insulated by the partition wall 23 and the hood 25,and noise caused by exhaust can be inhibited from being transmitted to apassenger sitting in the vehicle chamber A.

Since the air outlet 41 a is opened at a position higher than the upperend 4 b of the front wheel, splashed water and splashed earth and sandcaused by the front wheel 4 can be prevented from entering the airoutlet 41 a. More specifically, the all terrain vehicle 1 according tothe present embodiment may be driven on a river, a marshy place, orearth road where the front wheels 4 and the rear wheels 5 are submerged.When the vehicle is driven on such an uneven ground, water, earth, andsand can be prevented from entering the air outlet 41 a.

Since the air outlet 41 a is opened downward and backward, rain water orwater in car wash can be prevented from entering the air outlet 41 afrom the above while the splashed water and earth and sand can beprevented from entering the air outlet 41 a.

In the present embodiment, since the air inlet port 40 a of the coolingair supply duct 40 is opened in the upper portion of the front chamberB, suction noise from the air inlet port 40 a is insulated by thepartition wall 23 and the hood 25. For this reason, the suction noisecan be inhibited from being transmitted to a passenger sitting in thevehicle chamber A.

Since the air inlet port 40 a is opened at a position higher than theupper end 4 b of the front wheel 4, splashed water and splashed earthand sand caused by the front wheels 4 can be prevented from entering theair outlet 41 a.

In the present embodiment, since the air inlet port 40 a is opened inthe housing box 43 in which in-vehicle parts such as the battery 49 andthe various electronic parts 50 are housed, the in-vehicle parts arecooled when cooling air passes through the inside of the housing box 43,cooling capability of the in-vehicle parts can be improved withoutproviding an additional cooling structure.

In present the embodiment, since the air inlet port 40 a and the airoutlet 41 a are separately arranged in the width direction of thevehicle, more specifically, since the air inlet port 40 a and the airoutlet 41 a are arranged with an interval which is ½ or more of thedimension in width of the vehicle, high-temperature exhaust air can bereliably prevented from flowing into the air inlet port 40 a. In thismanner, low-temperature air can be supplied, and cooling efficiency canbe improved.

In the present embodiment, since the intake port 35 a of the air cleaner35 to which the intake pipe 30 is connected is opened in the upperportion of the front chamber B in a side view, suction noise from theintake port 35 a can be insulated as described above, and the suctionnoise can be inhibited from being transmitted to a passenger in thevehicle chamber A.

Since the intake port 35 a is opened at a position higher than the upperend 4 b of the front wheel 4, as described above, splashed water andsplashed earth and sand caused by the front wheels 4 can be preventedfrom entering the intake port 35 a.

In the present embodiment, since the engine unit 3 is arranged in theconsole 24 behind the partition wall 23, for example, heat effect oncooling air or combustion air occurring when an engine is arranged belowa hood can be avoided, and low-temperature air can be supplied to thecontinuously variable transmission 21 and the engine 20.

In the present embodiment, the first seat 6 arranged on the front sideof the vehicle and the second seat 7 arranged behind the first seat 6are arranged, and the V-belt continuously variable transmission 21 isarranged below the first seat 6. For this reason, a seat level can belowered, and a passenger space for a passenger sitting on the first seatcan be secured.

When viewed from the side of the vehicle, the first seat 6 and theengine 20 are arranged to partially overlap. For this reason, in thisregard, the level of the first seat 6 can be lowered, and a passengerspace can be secured.

In the present embodiment, in a planar view, the intake pipe 30, thecooling air supply duct 40, and the cooling air exhaust duct 41 arearranged to partially overlap. As a result, the intake pipe 30 and eachof the ducts 40, 41 vertically overlap and therefore a piping space forthe intake pipe 30, the cooling air supply duct 40, and the cooling airexhaust duct 41 can be easily secured. Since the intake pipe 30 and theducts 40 and 41 serving as noise sources are close to each other, anoise insulating structure such as a structure in which the ducts arecovered with a cover can be simplified.

Since a portion of the intake pipe 30 arranged in the console 24 isarranged above portions of the cooling air supply duct 40 and thecooling air exhaust duct 41 in the passenger space, a piping space canbe easily secured again as described above, and a sound insulatingstructure can be simplified.

Since the surge tank 34 interposed in the middle of the intake pipe 30is arranged above the cooling air supply duct 40 and the cooling airexhaust duct 41, the surge tank 34 insulates noise from the cooling airsupply duct 40 and the cooling air exhaust duct 41. A space forarranging the surge tank 34 having a relatively large capacity can besecured. The console (projecting unit) 24 projecting upward from thefirst floor 8 as well as extending from the center portion in the widthdirection of the vehicle to the rear side in the front/rear direction ofthe vehicle, and the intake pipe 30, the cooling air supply duct 40, andthe cooling air exhaust duct 41 are arranged below the console 24 tooverlap the console 24 in planar view. For this reason, the console 24can inhibit suction noise, exhaust noise, and the like from beingtransmitted to a passenger.

Since the console 24 communicates with the front chamber B, the passagescan be arranged to extend from the engine unit 3 to the front chamber B,and the console 24 can be easily used as an engine arrangement space.

1. A method of cooling electrical components of a vehicle having anengine comprising: providing an air intake passageway for communicatingair from the ambient environment into said engine; providing an airexhaust passageway for communicating air from said engine to saidambient environment; providing a housing for electrical componentshaving an air inlet and an air outlet; communicating said air outlet ofsaid electrical component housing with said air intake passageway;directing air into said air inlet of said electrical component housingfor cooling electrical components; directing air from said housing forelectrical components to said engine via said air intake passageway; anddirecting air from said engine to said ambient environment through saidair exhaust passageway.